Daddy dearest, I did it for you

There are some deaths which, however unexpected, seem horribly inevitable. A painful example is Gerard Depardieu's son, Guillaume, who died on Monday at the age of 37, following an attack of viral pneumonia.

The life of Depardieu fils was always troubled. He spent years doing drugs. He was involved in several violent road accidents; he lost a leg in 2004. And all this despite possessing his own acting talents: he won a Cesar (a French Oscar) for his role in Les Apprentis in 1996.

So why was his life so fraught? As one obituary put it: he existed in "angry rebellion in the shadow of his celebrated father". This is a feeling I know well.

Admittedly my father, DM Thomas, has never been as famous as Gerard Depardieu. But in the realms of literature he was once a big star. His most famous novel, The White Hotel, sold 2 million copies in America. Graham Greene said the book was so fine it left him "speechless".

Having a father who is celebrated is deeply confusing. First of all, when you are young, comes the love and the pride: "My dad's bigger than your dad". But as you get older, the shadow begins to form. When you go places, you are introduced as "so and so's son" - not as yourself. That is pretty painful.

It is particularly painful if, thanks to genetics, you share some of your father's talent. From an early age I knew I had some skill as a writer. And yet I knew that if I became a writer there was always the risk - maybe the probability ­ that I would suffer by comparison.

I think that's why I turned to drugs, just like Guillaume Depardieu. Because I feared I couldn't beat my dad, especially at his own game - I decided I'd do the opposite: and have lots of nihilistic fun. I came close to overdoses; I did time in prison.

Naturally I don't blame all of this on my father - ­ I was "an idiot anyway", as Guillaume Depardieu said of himself. But the shadow was there ­ and it made any effort at real success seem valueless.

Nonetheless, writing was what I was good at: eventually, therefore, I became a journalist, and then a novelist. Yet the Oedipal conflicts remained. My literary fiction was still a conscious attempt to best my father.

This was brought home to me a few years ago when my dad called, to tell me they were going to make a Hollywood film of his book. Half of me was pleased for the old man, but the other half was angry: I had been enjoying his gentle decline since the 1980s, now he was back in the game. He was going to outrank me all over again.

It was a watershed moment: I realised there must be another way, that my straining to defeat my father was defeating myself. Moreover I was broke, and my novels had failed to flabbergast Graham Greene. So I decided to relax, and just do my own thing.

Soon after I wrote a comic sex memoir, Millions of Women Are Waiting to Meet You, which actually sold in several countries. Next year I'm publishing a thriller, The Genesis Secret, which is already being translated into 18 languages.

The book is not an attempt to win the Pulitzer, it's simply a ripping yarn that I enjoyed writing. But that, of course, is the point: this book is just me - not me trying to Out-Do Dad.

Put it another way: it's only when I stopped trying to be more successful than my father that I became quite successful. The irony might make a good novel.

'The Genesis Secret' will be published in the UK by Harper. 'Millions of Women Are Waiting to Meet You' is published by Bloomsbury. DM Thomas's 'The White Hotel' is published by Indigo ·